Biokeywords

	A
	abdomen	the part of your body containing most of the organs of your digestive system
	absorb, absorption	when cells or blood take in dissolved food or oxygen
	acid rain	rain made acidic by dissolved sulphur dioxide and nitrogen oxides
	adapted, adaptation	when plants or animals have features which make them suitable for where they live
	addicted	when a person can't do without a drug
	aerobic respiration	using oxygen to break down food to release energy
	alcohol	a chemical which can be used as a drug
	allele	a form of gene, eg. there is an allele for blue eyes
	alveoli	small air sacs in the lungs; one is called an alveolus
	amino acids	carbon compounds which proteins are built from
	anaerobic respiration	release of energy from food without the use of oxygen
	antibody	chemical made by white blood cells to destroy bacteria and other microbes
	antitoxin	chemical made by white blood cells to neutralise toxins
	anus	opening at the end of the digestive system
	arteries	blood vessels which carry blood away from the heart
	asexual reproduction	reproduction without sex, that is by a single animal or plant
	atria	upper chambers of the heart; one is called an 'atrium'
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	B
	bacteria	microbes made of cells with a chromosome which is not in a nucleus one is called a 'bacterium'
	biodegradable	made of material which microbes can break down or decay
	biomass	the material plants and animals are made of
	bladder	a stretchy bag which stores urine
	breathing	taking air in and out of the lungs
	breed (1)	reproduce or make new plants and animals
	breed (2)	one of several kinds of plant or animal within the same species
	bronchi	air tubes between the windpipe and the lungs; one is called a 'bronchus'
	bronchioles	tubes which branch from the bronchi into each lung
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	C
	capillary	narrow blood vessel with walls only one cell thick
	carbohydrase	enzyme which breaks down carbohydrates
	carbohydrates	carbon compounds used by living things as food, eg. starch and sugars
	carbon cycle	the recycling of carbon in nature
	carbon dioxide	a gas in the air used by plants in photosynthesis and made in respiration
	carbon monoxide	a poisonous gas
	cardiac muscle	heart muscle
	carriers	people who have a recessive allele for a gene for a disorder and can pass it on to their children, but who do not have the disease themselves
	catalyst	a substance which speeds up a chemical reaction and which can be used over and over again
	cell	the building block of plants and animals
	cell membrane	outer layer of the living part of a cell
	cell sap	a solution of sugars
	cell wall	outer supporting layer of a plant cell made of cellulose
	cellulose	the carbohydrate which makes up plant cell walls and the fibre in your diet
	characteristics	the special features of any plant or animal
	chlorophyll	the green substance in chloroplasts which traps light energy
	chloroplasts	the parts of plant cells which contain chlorophyll
	chromosome	structure made of genes found in the nucleus of a cell
	cilia	hair-like fringes on some cells which beat to make an air current or to move a cell
	ciliary muscle	muscle in the eye which changes the shape of a lens
	clones	groups of genetically identical living things
	combustion	burning
	community	a collection of species living in one particular place
	compete, competition	when several plants or animals are all trying to get the same things
	consumer	an animal which cannot make its own food, but gets it from plants or other animals
	contraceptive	a device or a drug used to prevent pregnancy
	contract	in the case of a muscle, to become shorter and fatter
	coordinate	to make the different parts of plants or animals work together
	cornea	transparent layer at the front of the eye
	cuttings	parts of plants cut off an older plant and grown into new plants
	cystic fibrosis	an inherited disorder of cell membranes
	cytoplasm	the contents of a cell excluding the nucleus, the place where most chemical reactions happen
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	D
	decay	to rot or break down
	decomposers	microbes which cause decay
	deoxygenated blood	blood containing very little oxygen
	diabetes	a disorder caused by shortage of insulin
	diaphragm	a sheet of muscle which separates your thorax (chest) from your abdomen
	diffuses, diffusion	the spreading of liquids and gases from where the concentration is high to where it is low
	digestion	breakdown of large, insoluble food molecules into small, soluble molecules which can be absorbed
	digestive system	all the organs which are used to digest food
	disease, disorder	when some part of a plant or animal isn't working properly
	Down's syndrome	an inherited disorder caused by an extra chromosome
	drug	a substance which can change the way your body works
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	E
	enzymes	protein substances made in cells which speed up chemical reactions and are not used up
	evolved	plant or animal species which have changed and developed over a long period of time
	excretion	getting rid of the waste made in chemical reactions in cells
	extinct	no longer existing
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	F
	faeces	undigested waste which passes out through the anus
	fat	part of our food which we use for energy and for making cell membranes
	fatty acids	one of the building blocks of fats
	fertilise, fertilisation	when a male sex cell joins with a female sex cell to start a new plant or animal
	fertiliser	you add this to soil to provide the minerals plants need to grow
	fertility	the ability to reproduce
	fibre	indigestible cellulose in our food (roughage)
	food chain	diagram showing what animals eat
	food web	diagram showing what eats what in a habitat
	fossil	remains of plants and animals from a long time ago
	fungi	plants which do not make their own food but break down dead bodies of plants and animals and other waste; one is called a fungus
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	G
	gametes	another name for sex cells
	gene	these control the characteristics of plants and animals; they are passed on by parents in chromosomes
	genetic	related to genes
	germicide	something which kills bacteria
	germinate	to begin to grow, e.g. a plant growing from the embryo in a seed
	glandular tissue	groups of cells which produce useful juices, e.g. digestive juices
	global warming	increase in the average temperature on Earth
	glucagon	a hormone made in the pancreas which makes liver cells release glucose
	glucose	a carbohydrate made of small, soluble molecules (a sugar)
	glycerol	one of the building blocks of fats
	gravity	the downward pull of the Earth
	grow, growth	to become bigger and more complicated
	guard cells	cells around the stomata (pores) in the skin of a leaf
	gullet	the tube that goes from the mouth to the stomach; another name for the oesophagus
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	H
	habitat	the place where a plant or animal lives
	haemoglobin	chemical in red blood cells which carries oxygen
	heart	an organ which pumps blood
	herbicide	weedkiller
	hormones	chemicals secreted in small amounts which coordinate the growth and activities of living things
	Huntington's chorea	an inherited disorder of the nervous system
	hypothermia	when your body temperature falls below 35°C
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	I
	immune, immunity	when your body stops catching a particular infection
	infected, infection	when microbes get into your body and cause a disease
	inherited	passed on in the genes from parents to offspring
	insoluble	does not dissolve
	insulin	a hormone secreted by the pancreas which helps the blood control the blood glucose level
	iris	part of your eye which controls the size of your pupil
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	J
	joule (J)	the unit of energy
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	K
	kidneys	organs which remove urea from your blood and excrete it in your urine
	kilojoule (kJ)	1000 joules
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	L
	large intestine	wide part of the intestine between the small intestine and the anus
	lens	part of the eye which helps focus light on the retina
	lipase	enzyme which digests fat
	liver	large organ in the abdomen which works with your pancreas to control the level of glucose in your blood
	lungs	organs in which gases are exchanged between the blood and the air
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	M
	menstrual cycle	the monthly cycle in the human female reproductive system
	microbes	microscopic living things
	minerals	simple chemicals living things need in small amounts to stay healthy
	molecule	smallest part of any chemical substance
	motor neurons	nerve cells which carry impulses from the brain and the spinal cord to muscles
	mucus	sticky fluid made by some cells, e.g. in the bronchi to trap microbes and dirt
	muscular tissue	a group of muscle cells which contract to do work
	mutation	a change in the chromosome or a gene
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	N
	nervous system	the organ system which coordinates the activities of the body
	nicotine	a drug in tobacco to which people can become addicted
	nitrogen oxides	gases which pollute the air and are one of the causes of acid rain
	non-biodegradable	made of materials which microbes cannot break down
	nucleus	the part of a cell which controls what happens in the cell
	nutrients	food needed by animals, or minerals needed by plants
	nutrition	obtaining the materials needed for energy and making new cells
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	O
	oesophagus	another word for gullet
	optic nerve	the nerve which carries impulses from your eye to your brain
	organ	structure in a plant or animal made of several different tissues
	organ system	a group of organs which work together to do a particular job
	organic waste	waste which comes from living things
	ovaries	where egg cells (female gametes) are made
	oviduct	egg tube where fertilisation happens
	ovule	contains the female gamete of a flowering plant
	oxygen	a gas in the air used in aerobic respiration
	oxygenated blood	blood that is rich in oxygen
	oxyhaemoglobin	the chemical formed when oxygen joins with haemoglobin in red blood cells
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	P
	pancreas	the organ which makes pancreatic juice, glucagon and insulin
	pesticide	a chemical which kills pests
	phloem	tissue which transports sugars in plants
	photosynthesis	the process in which plants use light energy to make glucose from carbon dioxide and water
	pituitary gland	the gland in the base of the brain which produces hormones
	plasma	the liquid part of the blood
	platelets	bits of cells needed for clotting blood
	pollen grains	contains the male gamete of a flowering plant
	pollute, pollution	to contaminate the environment with undesirable materials or energy
	population	all the plants or animals of one species which live in a particular place
	predator	an animal which eats other animals
	prey	an animal which is eaten by another animal
	producer	an organism (usually a green plant) which makes its own food
	protease	enzyme which digests protein
	protein	the part of your food which you need for growth and repair
	pulse	the stretching of an artery each time your heart beats
	pupil	an opening in the iris of your eye which lets light through to your retina
	pyramid of biomass	pyramid-shaped diagram showing the decrease in biomass as you go up a food chain
	pyramid of number	pyramid-shaped diagram showing how the numbers of organisms change as you go up a food chain
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	Q
	R
	receptors	sensory cells, cells which detect stimuli
	recycling	using materials over and over again
	red blood cells	cells in the blood which carry oxygen as oxyhaemoglobin
	reproduce, reproduction	to breed or make offspring
	respiration	the breakdown of food to release energy in living cells
	retina	the layer of light sensitive cells lining the eye
	root hair	plant roots absorb water and minerals mainly through these
	rooting hormone	hormone which stimulates root growth in a cutting
	runners	stems growing along the ground from which new plants grow
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	S
	saliva	digestive juice made by salivary glands
	salivary glands	glands in the mouth which produce saliva
	sclera	tough, white outer coat of the eye
	selective breeding	breeding only from the plants or animals which have the characteristics we want
	sense organ	organ which detects stimuli, eg. the eye
	sensitive, sensitivity	able to detect changes in the surroundings and react to them
	sensory neurons	nerve cells which connect receptors to the brain and spinal cord
	sewage	watery waste which goes into the sewers
	sex cells	cells which join to form new plants or animals; also called gametes
	sexual reproduction	when new plants or animals are made from sex cells
	sickle cell disease	an inherited disorder of the red blood cells
	small intestine	the narrow part of the intestine between the stomach and the large intestine; digestion finishes and absorption finishes here
	soluble	able to dissolve
	solvent	a chemical in which other substances will dissolve; some solvents are drugs
	specialised	particularly suited or adapted to do a particular job
	species	we say that plants or animals which can breed with each other belong to the same species
	sperm	male sex cell (or gamete)
	starch	a carbohydrate made from large insoluble molecules
	stimuli	changes in the surroundings to which living things respond; one is called a stimulus
	stomach	an organ in the digestive system
	stomata	pores in the skin of a leaf
	sulphur dioxide	a poisonous gas which pollutes the air and is one of the causes of acid rain
	suspensory ligament	the ligament which holds the lens of the eye in place
	sweat glands	glands in the skin which produce sweat; this evaporates to cool the skin
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	T
	taste buds	groups of cells on the tongue sensitive to some chemicals
	thorax	the chest; the part of the body which contains the heart and the lungs
	tissue	a group of cells with the same shape and job
	toxins	substances which are poisonous (toxic)
	trachea	another word for windpipe
	transpiration	the loss of water vapour from plants through leaf pores (stomata)
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	U
	urea	the poisonous waste made when the liver breaks down amino acids
	urine	the liquid containing water, salts and urea excreted by the kidneys
	uterus	where a baby develops before birth; also called the womb
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	V
	vacuole	space filled with cell sap in the cytoplasm of a plant cell
	valves	these stop blood flowing the wrong way
	variations	differences
	variety	another word for breed
	veins	blood vessels which carry blood towards the heart
	ventricles	the two thick-walled lower chambers of the heart
	viruses	microbes which can only live inside other cells
	vitamins	substances in food which we need in small amounts to stay healthy
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	W
	white blood cells	cells in the blood which help to destroy microbes and the toxins they produce
	windpipe	the tube between your throat and your bronchi
	withdrawal symptoms	unpleasant symptoms people get when they try to do without a drug they are dependent on
	womb	another word for uterus
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	X
	X chromosome	human sex chromosome; males have one, females have two
	xylem	the tissue in plants which transport water and salts
	Y
	Y chromosome	human sex chromosome causing maleness
	yield	how much food a plant crop or farm animal can produce
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	Z